TW202123332A - Grinding apparatus completing a grinding process without changing a grindstone for all wafers in a cassette in a grinding apparatus - Google Patents

Abstract

This invention aims to complete a grinding process without changing a grindstone for all wafers in a cassette in a grinding apparatus. A grinding apparatus comprises: a processing condition setting unit for setting processing conditions including a grindstone type and a grinding feed speed; a consumption amount data representing the consumption of a grindstone when a single wafer is ground under the set processing conditions; a wafer quantity setting unit for setting the number of wafers stored in the cassette; a cumulative consumption amount calculation unit that calculates the cumulative consumption amount of the grindstone when all the wafers stored in the cassette are ground by a formula with reference to the consumption amount data, wherein the formula is: the consumption amount of the grindstone per wafer * the number of wafers set from wafer quantity setting unit; a remaining amount recognition unit that recognizes the remaining amount of the grindstone; and a determination notification unit for, if the value obtained by subtracting the calculated cumulative consumption amount from the recognized remaining amount of grindstone before the start of processing becomes less than the allowable remaining amount of grindstone, determining that the grindstone will be exhausted before the grinding of all the wafers in the cassette is completed and performing notification.

Description

Grinding device

The invention relates to a grinding device for grinding a wafer with a grinding stone.

A grinding device that uses a grinding grindstone to grind a wafer held in a holding mechanism. The grinding grindstone is worn out by the grinding of the wafer. Therefore, even if the grinding grindstone is exhausted, it is performed During the processing, the operator will still be notified in order to replace the grinding stone. And, after the notification appears, the worker will replace the grinding grindstone with a new grinding grindstone.

As disclosed in Patent Document 1, for example, in the grinding process, the device recognizes the remaining amount of the grinding stone in a sequential and instantaneous manner, and further, each time a wafer is ground, the grinding stone is After subtracting the remaining amount from the grinding stone consumption calculated from the height of the grinding mechanism at the end of the grinding, the above notification will be made if the remaining amount of the grinding stone becomes smaller than the threshold value set in advance. Prior art literature Patent literature

Patent Document 1: Japanese Patent Application Publication No. 2015-036170

The problem to be solved by the invention

In the grinding device, for example, 25 wafers are stored in a wafer cassette, and the wafers are taken out from the cassette one by one to continuously perform grinding. Therefore, if the above notification is issued when, for example, 5 wafers are ground, the grinding stone may be replaced in the middle of the grinding of 25 wafers.

In addition, due to the replacement of the grinding grindstone, there is temporarily no grinding grindstone rotating in the processing chamber or the processing chamber is released to the outside air, thereby causing fluctuations in the temperature in the processing chamber. This temperature change may cause the thickness of the wafer after grinding to be different from wafer to wafer before and after the grinding stone is replaced. Accordingly, there is the following problem: in a grinding device that grinds a wafer with a grinding stone, the grinding process of all the wafers in the cassette is completed without replacing the grinding stone. Means to solve the problem

The present invention for solving the above-mentioned problems is a grinding device including: a holding mechanism for holding a wafer by a holding surface; a grinding mechanism for installing a grinding stone and holding a wafer in the holding mechanism Grinding; grinding and feeding mechanism, the grinding mechanism and the holding mechanism are opposite to the holding mechanism in a direction perpendicular to the holding surface grinding and feeding; cassette stage, placing a plurality of wafers can be accommodated And a transport mechanism for transporting wafers between the cassette and the holding mechanism, the aforementioned grinding device uses the grinding stone to grind the wafers stored in the cassette, and includes: The processing condition setting unit sets processing conditions including at least the type of the grinding stone and the feed speed of the grinding feed mechanism in order to use the grinding stone to grind the wafer; The consumption data indicates the consumption of the grinding stone when grinding a wafer under the set processing conditions; The wafer number setting section sets the number of wafers stored in the cassette; The cumulative consumption calculation part refers to the consumption data, and calculates the cumulative consumption of the grinding stone when all the wafers stored in the cassette are ground by a formula, wherein the aforementioned formula is: each piece The consumption of the grinding stone of the wafer × the number of wafers that have been set in the wafer number setting section; The remaining amount identification part identifies the remaining amount of the grinding stone; and The judgment notification unit, before the start of processing, deducts the accumulated consumption amount calculated by the accumulated consumption amount calculation unit from the remaining amount of the grinding stone identified by the remaining amount identification unit When the value is below the allowable value for the remaining amount of the grindstone, it is determined that the grinding grindstone will be exhausted before the completion of the grinding of all the wafers in the cassette, and a notification is made. Invention effect

In the past, notification of the replacement of the grinding grindstone was sometimes performed during the grinding process, and the following situation occurred: it is impossible to use the same grinding grindstone and almost the same processing for multiple wafers stored in the cassette The room temperature is used for grinding. According to this, the following situation has occurred: the thickness of a plurality of wafers after grinding is not uniform. However, the grinding device of the present invention is provided with: a processing condition setting unit that sets processing conditions including at least the type of the grinding stone and the feed speed of the grinding feed mechanism in order to use the grinding stone to grind the wafer. ;Consumption data, indicating the consumption of grinding stones when grinding a wafer under the set processing conditions; the number of wafers setting section, set the number of wafers stored in the cassette; cumulative consumption The amount calculation part refers to the consumption data and uses a formula to calculate the cumulative consumption of the grinding stone when all the wafers stored in the cassette are ground. The aforementioned formula is: grinding of each wafer The consumption of the grindstone × the number of wafers that have been set in the wafer number setting section; the remaining amount identification section, which identifies the remaining amount of the grindstone; and the judgment notification section. When the remaining amount of the grinding stone identified by the remaining amount identification unit subtracting the accumulated consumption amount calculated by the accumulated consumption amount calculation unit has become less than the allowable value of the remaining amount of grindstone, it is judged to be grinding The grindstone will be exhausted before the completion of the grinding of all the wafers in the cassette, and a notification will be given. This will inform the operator before the grinding process that there will be a need to complete the processing of the wafers that have been stored in the cassette. The grinding stone is replaced before the grinding of all wafers. Therefore, if there is a notice, the operator can replace the grinding stone before the grinding process and start the grinding process afterwards, so The processing results including the thickness and the like of the processed multiple wafers can be formed more uniformly.

The form used to implement the invention

The grinding apparatus 1 shown in FIG. 1 is an apparatus for grinding the wafer W held by the holding mechanism 30 by the grinding mechanism 4. The front (-Y direction side) on the base 10 of the grinding device 1 is the loading/unloading area A, which is the area where the wafer W is carried in and out of the holding mechanism 30, and the rear on the base 10 (+Y direction side) This is the processing area B that is the area where the grinding process of the wafer W held on the holding mechanism 30 is performed by the grinding mechanism 4. Furthermore, the grinding device of the present invention may also be formed as the following structure: a dual-shaft grinding mechanism with a rough grinding mechanism and a fine grinding mechanism is used as the grinding mechanism, and the holding mechanism 30 holding the wafer W by a rotating turntable Positioned below each grinding mechanism.

In this embodiment, the wafer W shown in FIG. 1 is a circular semiconductor wafer composed of a silicon base material, etc., and a plurality of devices are formed on the front surface Wa of the wafer W facing downward in FIG. 1. It is protected by being attached by a protective tape not shown in the figure. The back surface Wb of the wafer W facing the upper side becomes the surface to be processed on which the grinding process is performed. Furthermore, in addition to silicon, the wafer W can also be made of gallium arsenide, sapphire, gallium nitride, resin, ceramic, or silicon carbide.

A first cassette stage 150 and a second cassette stage 151 are provided on the front side (-Y direction side) of the base 10, which can be placed on the first cassette stage 150 to store multiple pieces of processing in the form of a shelf The first cassette 150a of the previous wafer W, and the second cassette 151a for storing a plurality of processed wafers W in a rack form can be placed on the second cassette stage 151.

Behind the opening on the +Y direction side of the first cassette 150a, a robot 155 is arranged that can carry out the wafer W before processing from the first cassette 150a and carry the processed wafer W into the second cassette 151a. . A temporary placement area 152 is provided at a position adjacent to the robot 155, and an alignment mechanism 153 is provided in the temporary placement area 152. The alignment mechanism 153 is used to align the wafer W carried out from the first cassette 150a and placed in the temporary placement area 152 to a predetermined position (centering) by performing alignment pins with a reduced diameter.

At a position adjacent to the aligning mechanism 153, a loading arm 154a that is wound while holding the wafer W is arranged. The loading arm 154a holds the wafer W that has been aligned in the alignment mechanism 153 and transports it to the holding mechanism 30 arranged in the processing area B. An unloading arm 154b is provided next to the loading arm 154a to wind around while holding the processed wafer W. At a position close to the unloading arm 154b, a single-piece cleaning mechanism 156 that cleans the processed wafer W transported by the unloading arm 154b is arranged. The wafer W that has been cleaned and dried by the cleaning mechanism 156 is carried into the second cassette 151a by the robot 155.

In this embodiment, the robot 155, the loading arm 154a, and the unloading arm 154b constitute a transport mechanism that transports the wafer W between the first cassette 150a and the second cassette 151a and the holding mechanism 30.

The holding mechanism 30 which is arranged on the base 10 of the grinding apparatus 1 and holds the wafer W is, for example, a circular shape in a plan view and a holding surface 30a which communicates with the suction unit (not shown). The source is composed of a porous member or the like and can attract and hold the wafer W. In addition, the holding mechanism 30 is surrounded by a cover 39 and can be moved back and forth in the Y-axis direction on the base 10 by a Y-axis-direction feed mechanism not shown. The aforementioned Y-axis-direction feed mechanism It is arranged under the cover 39 and the bellows cover 39a connected to the cover 39. In addition, the holding mechanism 30 is formed to be rotatable with the rotation axis in the Z-axis direction as the center.

A pillar 12 is erected at the rear (+Y direction side) of the processing area B, and a grinding feed mechanism 2 is arranged on the front surface of the pillar 12 on the -Y direction side. The aforementioned grinding feed mechanism 2 is used for grinding The mechanism 4 is opposed to the holding mechanism 30 by grinding and feeding in the Z-axis direction (vertical direction) perpendicular to the holding surface 30a. The grinding and feeding mechanism 2 includes a ball screw 20 having an axis in the Z-axis direction, a pair of guide rails 21 arranged in parallel with the ball screw 20, and a motor that is connected to the upper end of the ball screw 20 and rotates the ball screw 20 22. The inner nut is screwed to the ball screw 20 and the side slidably connected to the lifting plate 23 of the guide rail 21, and the holder 24 connected to the lifting plate 23 and holding the grinding mechanism 4, when the motor 22 rotates the ball screw 20 When moving, the lifting plate 23 is guided by the guide rail 21 and moves back and forth in the Z-axis direction along with this, and the grinding mechanism 4 held by the holder 24 is ground and fed in the Z-axis direction.

The grinding mechanism 4 that grinds the wafer W held on the holding mechanism 30 includes a rotating shaft 40 whose axial direction is the Z-axis direction, a housing 41 that supports the rotating shaft 40 so as to be rotatable, and a rotating drive rotating shaft 40. The motor 42, an annular mounting base 43 connected to the lower end of the rotating shaft 40, and a grinding wheel 44 detachably mounted on the lower surface of the mounting base 43.

The grinding wheel 44 includes a wheel base 441 and a plurality of substantially rectangular parallelepiped grinding stones 440 arranged on the bottom surface of the wheel base 441 in an annular manner. The grinding grindstone 440 is formed by fixing grinding abrasive grains with a predetermined adhesive or the like, for example.

A flow path (not shown) which is a passage of grinding water penetrates through the inside of the rotation shaft 40 in the axial direction (Z-axis direction) of the rotation shaft 40, and is formed. This flow path passes through the mounting seat 43 and opens on the bottom surface of the wheel base 441 so that grinding water can be sprayed toward the grinding stone 440.

A thickness measuring mechanism 38 is arranged at a position near the grinding wheel 44 that has been lowered to the height position when the wafer W is ground. The thickness measuring mechanism 38 measures the crystal by a contact method, for example, during grinding. The thickness of the circle W. The thickness measuring mechanism 38 includes, for example, a pair of thickness measuring devices (height gauges), that is, a first thickness measuring device 381 for measuring the height position of the holding surface 30a of the holding mechanism 30, and a wafer W held by the holding mechanism 30 The second thickness measuring device 382 for measuring the height position of the ground surface, that is, the back surface Wb.

The first thickness measuring device 381 and the second thickness measuring device 382 have a contact piece that moves up and down in the vertical direction at each tip thereof and contacts each measurement surface. The first thickness measuring device 381 (the second thickness measuring device 382) is supported so as to be movable up and down, and is formed so as to be able to be pressed against each measurement surface with an appropriate force. The thickness measurement mechanism 38 uses the first thickness measurement device 381 to detect the height position of the holding surface 30a that becomes the reference surface, and the second thickness measurement device 382 detects the back surface that becomes the upper surface of the wafer W to be ground. The height position of Wb is calculated, and the difference between the detected values of the two is calculated, so that the thickness of the wafer W can be sequentially measured during grinding. Furthermore, the thickness measurement mechanism 38 may be a non-contact thickness measurement mechanism.

The grinding device 1 is equipped with a control mechanism 9 that controls the entire device. The control mechanism 9 is composed of a memory medium such as a CPU and a memory that perform arithmetic processing in accordance with a control program, and is connected through a wired or wireless (not shown) The communication path is electrically connected to the Y-axis direction feed mechanism not shown in the figure that moves the holding mechanism 30 in the Y-axis direction, and the grinding mechanism 4, etc., and can be sucked and held under the control of the control mechanism 9 The movement control of the holding mechanism 30 of the wafer W in the Y-axis direction, the positioning control of the grinding mechanism 4, and the control of the rotation of the grinding wheel 44 in the grinding mechanism 4, etc.

For example, the control mechanism 9 may be electrically connected to the motor 22 of the grinding feed mechanism 2 that moves the grinding mechanism 4 up and down. For example, in the case where the motor 22 is a servo motor, the rotary encoder of the servo motor is connected to the control mechanism 9 which also functions as a servo amplifier, and can be used after the output interface of the control mechanism 9 supplies the action signal to the servo motor , The rotation number of the servo motor is used as an encoding signal to output to the input interface of the control mechanism 9. In addition, the control mechanism 9 that has received the encoded signal can sequentially identify the movement amount of the grinding mechanism 4 according to the rotation angle of the servo motor, and thereby identify the height position of the grinding mechanism 4 in sequence.

For example, the grinding device 1 is provided with a touch panel 16 (or a keyboard of an accessory device, etc.) as an input mechanism for allowing an operator to input processing conditions and the like to the grinding device 1. For example, the touch panel 16 is electrically connected to the control mechanism 9 and detects the position touched by the operator with a finger, and sends a signal indicating the detection result to the control mechanism 9. On the touch panel 16, an input screen and a display screen can be displayed. The input screen allows the operator to input and set various information of the processing conditions in the grinding device 1, and the display screen can display the processing conditions Various information, the state of the ground back Wb of the wafer W, and the state of each part of the device, etc.

The grinding device 1 is provided with a processing condition setting unit 91 for setting processing including at least the type of the grinding stone 440 and the feed speed of the grinding feed mechanism 2 in order to use the grinding stone 440 to grind the wafer W Conditions; Consumption data 93, indicating the consumption of the grinding stone 440 when grinding a wafer W under the set processing conditions; The number of wafers setting unit 95 sets the number of wafers stored in the first cassette 150a The number of wafers W before processing; and the cumulative consumption calculation unit 96 refers to the consumption data 93 and calculates the grinding when all the wafers W stored in the first cassette 150a are ground by the formula The cumulative consumption of the grindstone 440, wherein the aforementioned formula is: [consumption of the grinding grindstone 440 per wafer W]×[the number of wafers W set in the wafer number setting section 95]. Furthermore, in addition to the operator inputting the number of wafers W before processing stored in the first cassette 150a to the wafer number setting unit 95 as described above, it can also be equipped with detection that has been stored in the first cassette. The sensor for the wafer W of the cassette 150a, and detects the number of wafers W stored in the first cassette 150a by detecting the wafer W with the sensor, and further sets it to Wafer number setting unit 95.

In this embodiment, the processing condition setting unit 91 is set in an area of the memory medium of the control mechanism 9, and when, for example, the operator is required to grind at least the abrasive grains (such as diamond abrasive grains, etc.) of the grinding grindstone 440 and the adhesive (For example, resin, metal, or ceramic (vitrified), etc.) The type determined by the combination, and the grinding feed rate of the grinding mechanism 4 performed by the grinding feed mechanism 2 are input as part of the processing conditions In the case of the touch panel 16 not shown, the processing condition can be set (memorized) in the processing condition setting unit 91. Furthermore, the rotation speed of the grinding wheel 44, the rotation speed of the holding mechanism 30 holding the wafer W, the type of the wafer W, the thickness of the finished product of the wafer W, etc., may be further included as settings in the processing condition setting. Part 91 of the processing conditions.

In this embodiment, the consumption data 93 is data stored in one area of the storage medium of the control mechanism 9. The consumption data 93 is, for example, data obtained in past experiments. Hereinafter, an example of a case where the consumption data 93 can be obtained will be described.

Among the processing conditions set in the processing condition setting section 91 of the grinding device 1, the type of the grinding stone 440 is type 1, and the grinding feed rate of the grinding mechanism 4 performed by the grinding feed mechanism 2 is Set the grinding feed rate V1. In addition, for example, the thickness of the first wafer W before grinding in the grinding process in the grinding device 1 is 300 μm, and the thickness of the finished wafer W is set to 100 μm.

As shown in FIG. 2, the holding mechanism 30 holding the wafer W is moved below the grinding mechanism 4, and the holding mechanism 30 is positioned so that the rotation center of the grinding wheel 44 of the grinding mechanism 4 is relative to the wafer W The rotation center of the grinding wheel 44 is offset by a predetermined distance in the horizontal direction, and the rotation track of the grinding wheel 44 passes the rotation center of the wafer W.

After that, under the control of the control mechanism 9 shown in FIG. 1, the motor 22 of the grinding feed mechanism 2 is driven to make the grinding mechanism 4 start from the predetermined origin shown in FIG. 2 which is grasped in advance. The height position gradually drops at a predetermined speed. In addition, the height position of the grinding mechanism 4 that has begun to descend can be grasped by the control mechanism 9 at any time. During the grinding process, the thickness measurement mechanism 38 measures the thickness of the wafer W sequentially in real time. The measurement result is transmitted to the control mechanism 9 shown in FIG. 1, and the grinding feed rate of the grinding mechanism 4 formed by the motor 22 is controlled to be close to the target product thickness, and the first wafer W is ground Cut to the thickness of the finished product (100μm).

Regarding the consumption of the grinding stone 440, the control mechanism 9 recognizes the grinding amount of the wafer W from the difference between the thickness of the wafer W before grinding and the thickness of the wafer W after grinding. And the control mechanism 9 can further recognize the grinding feed rate (lowering amount) of the grinding mechanism 4 from the height position Z0 when the grinding grindstone 440 is in contact with the back side Wb of the wafer W (that is, the amount before grinding) The difference between the height position Z0 of the grinding mechanism 4 and the height position Z1 of the grinding mechanism 4 at the end of grinding) is calculated as: [grinding feed amount of the grinding mechanism 4]-[by the thickness measuring mechanism 38 The measured grinding amount of the wafer W being ground]=[the consumption amount of the grinding stone 440]. For example, the initial consumption amount of the grinding stone 440 in the case where the first wafer W has been ground to the thickness of the finished product is the consumption amount L1. This consumption amount L1 is based on the reason that the grinding process performed on the first wafer W is not stable, or the setting (set-up) error occurs frequently, etc., so basically it cannot be used as the consumption amount data 93 .

Next, by performing the grinding process of the second wafer W shown in FIG. 3 in the same manner as described above, the wafer W can be ground to a finished product thickness of 100 μm, and the grinding process at the end of the grinding process can be identified. The height position Z2 of the grinding mechanism 4 is used to calculate the consumption L2 of the grinding stone 440 shown in FIG. 3. Because the grinding process of the second wafer W is carried out stably without setting errors, etc., the consumption L2 will become the set process condition (that is, at least the type of the grinding stone 440 is type 1 , The grinding feed rate of the grinding mechanism 4 performed by the grinding feed mechanism 2 is the processing condition of the grinding feed rate V1) the consumption of the grinding stone 440 when a wafer W is ground (Consumption data 93). Furthermore, it is also possible to further grind a plurality of wafers W to calculate the consumption of the grinding grindstone 440 for each piece of grinding, and the average of the plurality of consumptions is regarded as the consumption data 93. Also, the difference between the height position of the grinding mechanism 4 when the first wafer W is ground to the thickness of the finished product and the height position of the grinding mechanism 4 when the second wafer W is ground to the thickness of the finished product It is assumed that the consumption of the grinding stone 440 when one wafer W is ground (consumption data 93).

In addition to the consumption data 93 obtained as described above, the grinding device 1 may be provided with a plurality of consumption data that are different for each processing condition in the control mechanism 9.

As shown in FIG. 1, the grinding device 1 is provided with a remaining amount recognition unit 92 that recognizes the remaining amount of the grinding grindstone 440. The remaining amount recognition unit 92 is incorporated in, for example, the control mechanism 9. In addition, the remaining amount identification unit 92 is electrically connected to the grinding stone remaining amount detecting mechanism 35 shown in FIG. 1 through a wired or wireless communication path.

The non-contact type remaining amount of grindstone detection mechanism 35 is arranged on the cover 39 surrounding the holding mechanism 30, for example, and the remaining amount of grindstone detection mechanism 35 is made possible by a Y-axis direction feed mechanism not shown. Together with the holding mechanism 30 and the cover 39 that can reciprocate in the Y-axis direction, they reciprocate in the Y-axis direction. In addition, the arrangement position of the grindstone remaining amount detection mechanism 35 should just be a position below the grinding mechanism 4, and it is not limited to the structure on the cover 39, and may be formed to be movable.

The remaining amount of grindstone detection mechanism 35 is, for example, a reflection type (diffuse reflection type or limited reflection type, etc.) photoelectric sensor, and the light projecting unit 350 and the light receiving unit 351 are built in one sense amplifier. Furthermore, a shielding plate (not shown) may be provided between the holding mechanism 30 and the remaining grindstone detecting mechanism 35. The shielding plate prevents grinding debris from entering the remaining grindstone detecting mechanism from the holding mechanism 30 side. The situation on the side 35.

Hereinafter, the operation of each component of the grinding device 1 when the wafer W is ground by the grinding device 1 will be described. First, for example, an operator selects the processing conditions for the wafer W to be processed next from a plurality of processing conditions displayed on the input screen of the touch panel 16 and inputs the processing conditions to the control mechanism 9. The selected processing conditions are at least the type of the grinding stone 440 as type 1, and the grinding feed rate of the grinding mechanism 4 performed by the grinding feed mechanism 2 is the grinding feed rate V1. . The selected processing condition is set in the processing condition setting unit 91.

In addition, the operator inputs the number of wafers W stored in the first cassette 150 a before the grinding process to the control mechanism 9 from the input screen of the touch panel 16. Furthermore, the number of wafers W can also be set so that the grinding device 1 automatically grasps the wafers W placed in the first cassette 150a of the first cassette stage 150 by a sensor or the like. The composition of the number of pieces. The number of wafers W is set to 25, for example. Then, the number of wafers W can be set to 25 in the wafer number setting unit 95.

The cumulative consumption calculation unit 96 incorporated in the control mechanism 9 refers to the consumption data 93 of the memory medium stored in the control mechanism 9 to calculate [the consumption of the grinding stone 440 per wafer W]×[ The number of wafers W set in the wafer number setting section 95]=[Consumption L2 shown in Fig. 3]×25=all 25 wafers W stored in the first cassette 150a are ground The cumulative consumption L9 of the grinding stone 440 at the time.

In addition, the remaining amount of the grinding stone 440 installed in the grinding mechanism 4 can be recognized by the remaining amount of grinding stone detecting mechanism 35 and the remaining amount identifying unit 92. This remaining amount identification can be performed, for example, during the warm-up operation before the start of the machining of the grinding device 1. In this remaining amount identification, firstly, the grindstone remaining amount detecting mechanism 35 that moves together with the holding mechanism 30 is positioned at an arbitrary height as shown in FIG. 4 by a Y-axis direction feed mechanism not shown in the figure. The lower surface of the grinding stone 440 of the grinding mechanism 4 at the position Z3 is directly below. Then, the light projecting unit 350 of the remaining grindstone detection mechanism 35 irradiates the measurement light toward the lower surface of the grinding grindstone 440. Then, the measurement light reflected on the lower surface of the grinding stone 440 can be received by the light-receiving part 351 composed of CCD or the like, and the remaining amount from the grinding stone can be measured based on the optical triangulation measurement principle. The distance from the mechanism 35 to the lower surface of the grinding stone 440 in the Z-axis direction. The distance is, for example, the distance La. The information about the distance La can be transmitted from the grinding stone remaining amount detection mechanism 35 to the control mechanism 9 and stored in the control mechanism 9.

Next, the grindstone remaining amount detecting mechanism 35 is positioned directly below the lower surface of the wheel base 441 of the grinding mechanism 4 by a Y-axis direction feed mechanism not shown. Furthermore, the height position Z3 of the grinding mechanism 4 is maintained. Then, the light projecting unit 350 of the grindstone remaining amount detecting mechanism 35 irradiates the measurement light toward the lower surface of the wheel base 441. Then, by receiving the measurement light reflected on the lower surface of the wheel base 441 by the light receiving unit 351, the distance Lc in the Z-axis direction from the grindstone remaining amount detecting mechanism 35 to the lower surface of the wheel base 441 can be measured. The information about the distance Lc is transmitted from the grinding stone remaining amount detection mechanism 35 to the control mechanism 9 and stored in the control mechanism 9.

The remaining amount recognition unit 92 incorporated in the control mechanism 9 recognizes the value obtained by subtracting the distance La from the distance Lc as the remaining amount of the grinding stone 440. For example, it becomes [distance Lc]~[distance La]=the remaining amount Ld of the grinding stone 440.

The recognition of the remaining amount of the grinding stone 440 is not limited to the above-mentioned embodiment. For example, the grinding device 1 may be provided with a contact-type grindstone remaining amount detection mechanism 36 shown in FIG. 6 instead of the grindstone remaining amount detection mechanism 35. The grinding stone remaining amount detection mechanism 36 is provided with, for example, a contacted lift portion 365 that can be raised and lowered in contact with the lower surface of the grinding stone 440 or the lower surface of the wheel base 441, and the contacted lift portion 365 can be moved on the Z axis. The housing 360 that is housed in a manner of lifting in the direction, the elastic member 364 such as a spring that is arranged on the inner bottom surface of the housing 360 and is supported by the contact lifting portion 365 to be liftable, and the detection by the grinding feed mechanism 2 On the other hand, the lower surface of the descending grinding stone 440 or the lower surface of the wheel base 441 is in contact with the transmissive light sensor when the contacted lifting part 365 starts to descend. For example, the grinding stone remaining amount detection mechanism 36 can send various detection signals to the control mechanism 9 shown in FIG. 1 through a wireless or wired communication path (not shown).

The transmissive light sensor that detects when the lower surface of the falling grinding stone 440 or the lower surface of the wheel base 441 is in contact with the lifter 365 starts to descend. The light projecting unit 362 and the light receiving unit 363 are on the sides and face each other in the Y-axis direction. By being lowered by the contact lifter 365, the measuring light projected by the light projection unit 362 is blocked, whereby the light receiving unit 363 detects the decrease in the amount of received light, and can detect the lower surface of the grinding stone 440 or the wheel base. The bottom surface of 441 has been in contact with the contacted lift 365. Furthermore, the remaining amount of grindstone detection mechanism 36 is not limited to a transmissive photo sensor, it may be an electrostatic capacitance type proximity sensor, or it may be directly disposed on the upper surface of the contacted lift portion 365. It detects the pressure sensor that has contacted the lower surface of the grinding stone 440 or the lower surface of the wheel base 441.

The remaining amount of the grinding stone 440 is identified by the remaining amount detecting mechanism 36 and the remaining amount identifying unit 92 shown in FIG. 6. By the Y-axis direction feed mechanism not shown, for example, the grinding stone remaining amount detecting mechanism 36 that moves together with the holding mechanism 30 can be positioned directly below the lower surface of the grinding grind stone 440 of the grinding mechanism 4. Then, under the control performed by the control mechanism 9, the grinding feed mechanism 2 gradually lowers the grinding mechanism 4, which has been positioned to the height position grasped in advance, at a predetermined speed. In addition, the height position of the grinding mechanism 4 that has begun to descend can be grasped by the control mechanism 9 at any time.

For example, as shown in FIG. 6, when the lower surface of the grinding grindstone 440 of the descending grinding mechanism 4 contacts the upper surface of the contacted lifting portion 365, the contacted lifting portion 365 starts to descend, resulting in a transmissive light perception. The light-receiving part 363 of the sensor detects the decrease in the measurement light. The detection signal is sent from the grinding stone remaining amount detection mechanism 36 to the control mechanism 9, and under the control of the control mechanism 9, the grinding mechanism 4 by the grinding feed mechanism 2 is stopped in the -Z direction Grinding feed. In addition, the control mechanism 9 memorizes the height position of the grinding mechanism 4 at the point in time when the lower surface of the grinding stone 440 comes into contact with the upper surface of the contacted lifting portion 365. This height position is, for example, the height position Z4 shown in FIG. 6.

Next, as shown in FIG. 7, the grindstone remaining amount detecting mechanism 36 is positioned directly below the lower surface of the wheel base 441 of the grinding mechanism 4 by a Y-axis direction feed mechanism not shown. Then, under the control performed by the control mechanism 9, the grinding feed mechanism 2 gradually lowers the grinding mechanism 4, which has been positioned to the height position grasped in advance, at a predetermined speed.

For example, as shown in FIG. 7, the lower surface of the wheel base 441 of the descending grinding mechanism 4 contacts the upper surface of the contacted elevating portion 365, and the light receiving portion 363 of the photo sensor detects the decrease in the measurement light. A detection signal is sent from the grinding stone remaining amount detection mechanism 36 to the control mechanism 9, and under the control of the control mechanism 9, the grinding feed of the grinding mechanism 4 in the -Z direction is stopped. In addition, the control mechanism 9 recognizes the height position Z5 of the grinding mechanism 4 at the point in time when the lower surface of the wheel base 441 is in contact with the upper surface of the contacted lifting portion 365.

The remaining amount recognition unit 92 incorporated in the control mechanism 9 shown in FIG. 1 recognizes the value obtained by subtracting the height position Z5 from the height position Z4 shown in FIG. 7 as the remaining amount of the grinding stone 440. For example, it becomes [height position Z4]-[height position Z5]=the remaining amount Ld of the grinding stone 440.

The grinding device 1 is provided with a judgment notification unit 99 shown in FIG. 1. The judgment notification unit 99 is incorporated in the control mechanism 9 in this embodiment. The judgment notification unit 99 calculates the remaining amount Ld of the grinding stone 440 identified by the remaining amount identification unit 92 before the start of processing, subtracting the amount calculated by the cumulative consumption calculation unit 96 as described previously. The value L10 after the cumulative consumption L9.

In addition, the judgment notification unit 99 judges whether the calculated value L10 is equal to or less than the allowable value for the remaining amount of grindstone (for example, 0 μm) or exceeds the allowable value for the remaining amount of grindstone. For example, the value L10 has become 0 μm or less. In this case, it is determined that the grinding grindstone 440 will be exhausted before the grinding of all 25 wafers W in the first cassette 150a is completed. This determination may be displayed on the touch panel 16, or the result may be displayed. The speaker shown in the figure reports the judgment, and the operator is notified of the judgment. In this case, the operator who has recognized the judgment will grind the remaining amount of the grinding stone 440 installed in the grinding mechanism 4 as the remaining amount Ld before starting the grinding process of the wafer W The wheel 44 is replaced with a new grinding wheel 44. In addition, it can also be set that the allowable value of the remaining amount of the grinding stone 440 is preset to a few μm, for example, and before the start of the processing, from the grinding and grinding identified by the remaining amount identification unit 92 When the remaining amount Ld of the stone 440 is subtracted from the accumulated consumption L9 calculated by the accumulated consumption calculating unit 96 as described above, the value L10 is below the allowable value of the remaining grindstone, the judgment notification unit 99 The operator will be notified of the following notice: The grinding wheel 44 currently installed in the grinding mechanism 4 is not suitable for grinding all 25 wafers W.

Furthermore, for example, when the value L10 exceeds the allowable value of the remaining amount of the grindstone (for example, 0μm), it is determined that the grinding grindstone 440 of type 1 will not be in the first cassette 150a shown in FIG. The wafer W is exhausted before the grinding is completed, and in the fully automatic grinding apparatus 1 as in this embodiment, in order to start the grinding process of the wafer W, the robot 155 starts the grinding process from the first wafer. The cassette 150a unloads a wafer W. Furthermore, the allowable value of the remaining amount of the grindstone can be set to an integer including 0.

For example, when the grinding wheel 44 is replaced with a new grinding wheel and the grinding of the wafer W shown in FIG. 1 is started, the holding mechanism 30 is moved to the vicinity of the load arm 154a. In addition, the robot 155 pulls out a wafer W from the first cassette 150 a and moves the wafer W to the temporary placement area 152.

After the wafer W is centered on the temporary area 152 by the alignment mechanism 153, the loading arm 154a transfers the centered wafer W to the holding mechanism 30. Then, a suction source (not shown) is actuated, and the holding mechanism 30 sucks and holds the wafer W on the holding surface 30a with the back surface Wb exposed upward.

Next, the holding mechanism 30 shown in FIG. 1 holding the wafer W is moved in the +Y direction to below the grinding mechanism 4. The grinding mechanism 4 is fed in the -Z direction by the grinding feed mechanism 2 at a grinding feed speed V1, and the grinding wheel 44 rotates with the rotation of the rotating shaft 40. Type 1 grinding grindstone 440 abuts on the back surface Wb of the wafer W to perform grinding. During the grinding, the wafer W held on the holding surface 30 a also rotates with the rotation of the holding mechanism 30, so the grinding wheel 44 can perform grinding processing of the entire surface of the back surface Wb of the wafer W. In addition, as grinding water is supplied to the contact portion of the grinding grindstone and the wafer W, the contact portion can be cooled, and the grinding debris generated at the contact portion can be washed and removed.

After the wafer W is ground to a desired thickness (for example, a thickness of 100 μm), the grinding mechanism 4 is lifted by the grinding feed mechanism 2 to move it away from the wafer W, and the holding mechanism 30 is further moved toward − It moves in the Y direction and is positioned near the unloading arm 154b. Next, the wafer W on which the back surface Wb has been sucked and held by the unloading arm 154b is transported to the cleaning mechanism 156. The back surface Wb of the wafer W is rotated and cleaned by the cleaning mechanism 156, and after further drying, it is carried into the second cassette 151a by the robot 155.

The 25 wafers W stored in the first cassette 150a are sequentially subjected to the grinding process as described above to complete the grinding process of all the wafers W in the first cassette 150a.

As described above, the grinding device 1 of the present invention is provided with the processing condition setting unit 91 for setting at least the type of the grinding stone 440 and the grinding feed mechanism 2 in order to use the grinding stone 440 to grind the wafer W. The processing conditions of the feed speed; the consumption data 93 indicates the consumption of the grinding stone 440 when grinding a wafer W under the set processing conditions; the wafer number setting unit 95, the setting has been stored in The number of wafers W in the first cassette 150a; the cumulative consumption calculation unit 96 refers to the consumption data 93, and calculates by a formula when all the wafers W stored in the first cassette 150a are ground The cumulative consumption of the grinding stone 440, where the aforementioned formula is: consumption of the grinding stone 440 per wafer W×the number of wafers W set in the wafer number setting section 95; remaining quantity The recognition unit 92 recognizes the remaining amount of the grinding grindstone 440; and the judgment notification unit 99, before processing starts, if the remaining amount of the grinding grindstone 440 identified by the remaining amount recognition unit 92 is deducted by When the cumulative consumption value calculated by the cumulative consumption calculation unit 96 is below the allowable value of the remaining grindstone, it is determined that the grinding stone 440 will complete all the wafers W in the first cassette 150a. Before the grinding process is exhausted, and a notification is made, so that the operator can be notified before the start of the grinding process that it will be necessary to complete the grinding process of all the wafers W stored in the first cassette 150a In the case of replacing the grinding stone 440, the operator can replace the grinding stone 440 with one that can grind all the wafers W in the first cassette 150a before the grinding process if there is a notice. The new grinding stone 440 is subjected to grinding processing afterwards, so the processing results including the thickness of the plurality of wafers W to be processed can be made more uniform.

In addition, the grinding device 1 of the present invention is not limited to the device of the above-mentioned embodiment, and the various configurations shown in the attached drawings are not limited to this, and can be within the range where the effects of the present invention can be exhibited. Make appropriate changes.

For example, the calculation of the consumption of the grinding grindstone 440 when grinding a wafer W under the set processing conditions is not limited to the example of calculation as described above, and may be calculated by, for example, a remaining amount of grindstone detection mechanism. 36 and the remaining amount identification unit 92 to measure the remaining amount of the grinding stone 440 before grinding a wafer W, and to further measure the remaining amount of the grinding stone 440 after grinding the wafer W , And calculate the difference between the remaining amount of grindstone before and after grinding to find the consumption.

For example, in the present embodiment, although the grinding process of the wafer W is performed under the same processing conditions as in the past when the grinding process of the wafer W is performed, the processing conditions have not been performed in the past. When the wafer W is subjected to grinding processing, the wafer W or dummy wafer is used, and the new processing conditions are set to the processing condition setting unit 91 before the grinding processing is started to perform processing experiments, and the obtained ones The resultant consumption data is memorized in the control mechanism 9 again.

1: Grinding device 10: Pedestal 12: Pillar 150: The first cassette stage 150a: The first cassette 151: 2nd cassette stage 151a: second cassette 152: Temporary Area 153: Counterpoint 154a: Loading arm 154b: Unloading arm 155: Robot 156: Washing mechanism 16: touch panel 2: Grinding feed mechanism 20: Ball screw 21: Rail 22: Motor 23: Lifting board 24: retainer 30: Keep the organization 30a: Keep the face 35: grindstone remaining quantity detection mechanism 350: Projection Department 351: Light Receiving Department 36: grindstone remaining quantity detection mechanism 360: cover 362: Projection Department 363: Light Receiving Department 364: Elastic member 365: contacted lifting part 38: Thickness measuring mechanism 381: The first thickness measuring device 382: The second thickness measuring device 39: cover 39a: Snake belly cover 4: Grinding mechanism 40: Rotation axis 41: Shell 42: Motor 43: Mounting seat 44: Grinding wheel 440: Grinding Stone 441: Wheel Abutment 9: Control mechanism 91: Processing condition setting section 92: Remaining amount recognition section 93: Consumption data 95: Wafer number setting section 96: Cumulative consumption calculation department 99: Judgment Notification Department A: Moving in and out of the area B: Processing area L1, L2: consumption L9: Cumulative consumption L10: value La,Lc: distance Ld: remaining amount W: Wafer Wa: front Wb: back Z0, Z1, Z2, Z3, Z4, Z5: height position X,+X,-X,+Y,-Y,+Z,-Z: direction

Fig. 1 is a perspective view showing an example of a grinding device. Fig. 2 is a cross-sectional view explaining how the first wafer is ground to the thickness of the finished product. 3 is a cross-sectional view illustrating the consumption of the grinding grindstone when the consumption data is obtained by grinding the second wafer. 4 is a cross-sectional view illustrating a state in which measurement light is irradiated from a non-contact type remaining amount detecting mechanism of the grinding stone to the lower surface of the grinding stone in order to recognize the remaining amount of the grinding stone by the remaining amount recognition unit. 5 is a cross-sectional view illustrating a state in which measurement light is irradiated from a non-contact type remaining amount detecting mechanism of the grindstone to the lower surface of the wheel base in order to recognize the remaining amount of the grinding stone by the remaining amount recognition unit. 6 is a cross-sectional view illustrating a state where the lower surface of the grinding stone is brought into contact with a contact type remaining amount detecting mechanism of the grinding stone in order to recognize the remaining amount of the grinding stone by the remaining amount recognition unit. Fig. 7 is a cross-sectional view illustrating a state where the lower surface of the wheel base is in contact with a contact-type grindstone remaining amount detecting mechanism in order to recognize the remaining amount of the grinding stone by the remaining amount recognition unit.

1: Grinding device

10: Pedestal

12: Pillar

150: The first cassette stage

150a: The first cassette

151: 2nd cassette stage

151a: second cassette

152: Temporary Area

153: Counterpoint

154a: Loading arm

154b: Unloading arm

155: Robot

156: Washing mechanism

16: touch panel

2: Grinding feed mechanism

20: Ball screw

21: Rail

22: Motor

23: Lifting board

24: retainer

30: Keep the organization

30a: Keep the face

35: grindstone remaining quantity detection mechanism

350: Projection Department

351: Light Receiving Department

38: Thickness measuring mechanism

381: The first thickness measuring device

382: The second thickness measuring device

39: cover

39a: Snake belly cover

4: Grinding mechanism

40: Rotation axis

41: Shell

42: Motor

43: Mounting seat

44: Grinding wheel

440: Grinding Stone

441: Wheel Abutment

9: Control mechanism

91: Processing condition setting section

92: Remaining amount recognition section

93: Consumption data

95: Wafer number setting section

96: Cumulative consumption calculation department

99: Judgment Notification Department

A: Moving in and out of the area

B: Processing area

W: Wafer

Wa: front

Wb: back

+X, -X, +Y, -Y, +Z, -Z: direction

Claims (1)

A grinding device is provided with: a holding mechanism that holds a wafer by a holding surface; a grinding mechanism that installs a grinding stone and grinds the wafer held in the holding mechanism; and a grinding feed mechanism, The grinding mechanism and the holding mechanism are opposed to the holding mechanism for grinding and feeding in a direction perpendicular to the holding surface; a cassette stage, on which a cassette capable of accommodating a plurality of wafers is placed; and a transport mechanism, in the cassette The wafer is transported between the holding mechanism and the holding mechanism, and the aforementioned grinding device uses the grinding stone to grind the wafer stored in the cassette, and is provided with: The processing condition setting unit sets processing conditions including at least the type of the grinding stone and the feed speed of the grinding feed mechanism in order to use the grinding stone to grind the wafer; The consumption data indicates the consumption of the grinding stone when grinding a wafer under the set processing conditions; The wafer number setting section sets the number of wafers stored in the cassette; The cumulative consumption calculation part refers to the consumption data, and calculates the cumulative consumption of the grinding stone when all the wafers stored in the cassette are ground by a formula, wherein the aforementioned formula is: each piece The consumption of the grinding stone of the wafer×the number of wafers that have been set in the wafer number setting section; The remaining amount identification part identifies the remaining amount of the grinding stone; and The judgment notification unit, before the start of processing, deducts the accumulated consumption amount calculated by the accumulated consumption amount calculation unit from the remaining amount of the grinding stone identified by the remaining amount identification unit When the value is equal to or less than the allowable value for the remaining amount of the grindstone, it is determined that the grinding grindstone will be exhausted before the grinding of all the wafers in the cassette is completed, and a notification is made.

Images